1. HaldaneJ.B.S. ‘Daedalus, or Science and the Future’, Kegan Paul, Trench, Trubner & Co. London. 1924.
2. BeveridgeW.I.B. ‘Seeds of Discovery’ p. 78. Heinemann, London. 1980.
3. MephamT.B. ‘Physiology of Lactation’.p. 178. Open University Press, Milton Keynes: Philadelphia. 1987.